Pesticidal composition containing omicron, omicron-dimethyl-omicron-(3-methyl-4-nitrophenyl) phosphorothioate and omicron, omicron-dimethyl-omicron-(2, 2-dichlorovinyl) posphate



3,293,122 Umted States Patent cc Patented Dem 20, 1966 phosphorothioate and 0,0-dimethyl-O-(2,2-dichlorovinyl) 3293122 phosphate.

PESTICIDAL COMPOSITXON CONTAINING 0,0-DI- METHYL O (3 METHYL 4 NITROPHENYL) PHOSPHOROTHIOATE AND 0,0-DIMETHYL-O- (2,2-DICHLOROVINYL)PHOSPHATE Shinichi Suzuki, Sakai-511i, and Saichiro Kuramoto, Toyonaka-shi, Japan, assignors to Sumitomo Chemical Company, Ltd., Osaka, Japan, a corporation of Japan No Drawing. Filed Dec. 11, 1964, Ser. No. 417,779

Claims priority, application Japan, Dec. 26, 1963, 38/70,597 3 Claims. (Cl. 167-22) The present invention relates to pesticidal compositions containing, as the essential active ingredient, a mixture of 0,0-dimethyl-O-(3-methyl 4 nitrophenyl) phosphorothioate and 0,0-dimethyl-O-(2,2 dichlorovinyl) phosphate. More particularly, it relates to pesticidal compositions prepared by admixing 0,0-dimethyl O (3 methyl 4 nitrophenyl) phosphorothioate, 0,0-dirnethyl-O-(2,2-dichlorovinyl) phosphate and at least one carrier of terpene oil and pine oil. An object of the present invention is in the provision of novel pesticidal compositions with low cost which possess decreased toxicity towards plants, especially towards cruciferous plants, with increased pesticidal activity. Other objects would be apparent from the following descriptions.

The 0,0-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate is \a compound having extremely lowtoxicity towards warm blooded animals and having extensive effectiveness and strong pesticidal activities, and is widely utilized. However, this compound is comparatively toxic to vegetables and fruit trees, and is especially toxic to cruciferous plants. Accordingly, this compound has the disadvantage that it can not be used in the cruciferous plants in spite of the strong pesticidal activities towards injurious pests of the cruciferous plants such as common cabbage worm (Pieris rapae), cabbage army worm (Barathra brassicae), and clay backed cutworm.

The present pesticidal composition is less toxic towards above described plants and has excellent pesticidal activities.

After wide researches, the present inventors have found that the composition prepared by admixing about equivalent amount of 0,0-dimethyl-O-(2,2-dichlorovinyl) phosphate and 0,0-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate and 40-85% by weight of terpene oil or pine oil based upon the weight of the above mixture of 0,0-dimethyl-O-(2,2-dichlorovinyl) phosphate and 0,0 dimethyl O (3 methyl 4 nitrophenyl) phosphorothioate, is not only capable of decreasing the above described chemical harm of 0,0-dimethyl-O-(3-methyl- 4-nitrophenyl) phosphorothioate to the vegetables and fruit trees especially to the cruciferous plants, and also have extremely high pesticidal activities by a synergistic effect as compared with the activities of each component alone.

It is preferred that the mixing proportion of 0,0- dimethyl O (3 methyl 4 nitrophenyl) phosphorothioate to 0,0-dimethyl-O-(2,2-dichlonovinyl) phosphate is about 1:1.

As to the mixing amount of the terpene or pine oil, the amount of -100 weight percent, especially 4085 weight percent is preferred, based upon the weight of the mixture of 0,0-dimethyl-O-(3-methyl-4-nitrophenyl) When this mixture is obtained as an emulsion, it is necessary to add an assistant agent such as xylene and emulsifier. As the emulsifier, .an anionic or a nonionic surface active agent or mixture of them may be employed.

The mixing order of the present composition is most preferably conducted as shown in the examples.

The present composition is extremely advantageous in the view point of cost in that a part of expensive 0,0- dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate is replaced by cheap 0,0-dimethyl-O-(2,2-dichlorovinyl) phosphate, and that the high pesticidal activities can be exhibited without lowering pesticidal activities even in an extremely lower concentration than the case of using 0,0 dimethyl O (3 methyl 4 nitrophenyl') phosphorothioate alone, and also the chemical harm to the cruciferous plants and the like can be decreased. This fact has not yet been described in the literature.

The following examples are given merely by way of illustration and not by way of limitation.

Example 1 The first emulsifiable concentrate prepared by mixing 25 g. of 0,0-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate, 22. g. of xylene and 4 g. of a surface active agent, Agrisol PA (a registered trade name of Kao 'Soap K.K and the second emulsifiable concentrate prepared by mixing 25 g. of 0,0-dimethyl-O-(2,2-dichlorovinyl phosphate, 21 g. of pine oil and 3 g. of the same surface active agent, are blended together and agitated vigorously. The thus-prepared emulsifiable concentrate is diluted l,0002,000 times with water and applied to a cruciferous plant. The emulsion shows excellent pesticidal activity to the injurious insect of the plant without chemical harm.

Example 2 The first emulsifiable concentrate prepared by mixing 20 g. of 0,0-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate, 22. g. of xylene and 10 g. of a surface active agent Argisol PA (a registered trade name of Kao Soap K.K.), and the second emulsifiable concentrate prepared by mixing 20 g. of 0,0-dimethyl-O-(2,2- dichlorovinyl) phosphate, 21 g. of pine oil and 7 g. of the same surface active agent, are blended together and agitated vigorously. The thus-prepared emulsifiable concentrate is diluted 800l,600 times with water and applied to a cruciferous plant. The emulsion shows excellent pesticidal activity to the injurious insect of the plant without chemical harm.

Example 3 The first emulsifiable concentrate prepared by mixing 25 g. of 0,0-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate, and 3.5 g. of a surface active agent Emulgator W (a registered trade name of Bayer AG), and the second emulsifiable concentrate prepared by mixing 25 g. of 0,0-dimethyl-O-(2,2-dichlorovinyl) phosphate, 43 g. of pine oil and 3.5 g. of the same surface active agent are blended together and agitated vigorously. The thus-prepared emulsifiable concentrate is diluted LOGO-2,000 times with water and applied to a cruciferous plant. The emulsion shows excellent pesticidal activity 1tno the injurious insect of the plant without chemical arm.

Example 4 TABLE I Rate of dilution Composition Name of plant X500 X1000 X2000 Cabbage A composition prepared in Example 1.

A composition prepared in Example 2.

A composition prepared in Example 3.

A 50% emulsifiable concentrate of 0,0-dimethyl-O- (3-methyl-4-nitrophenyl) phosphorothioate.

A composition prepared in Example 1.

A composition prepared in Example 2.

A composition prepared in Exam e 3.

A 50% emulsifiable concentrate of 0,0-dimethyl-O- (3-methyl-4-nitrophenyl) phosphorothioate.

Komatsuna (A kind of Chinese cabbage) Note: The test plants were at the stage of two true leaves which have been sown so as to grow 10 plants in a 15 cm. pot,

The each composition diluted to the fixed. concentration was sprayed in an amount of 10 cc. per pot.

In the above Table I. shows harmlessness and shows hanmfulness. As the number of increases, the chemical lharmtulness is large. 1 shows to be almost harmless.

Example 5 The synergistic eifect of pesticidal activity against clay backed cutworm is shown below, comparing with each activity of the component 0,0-dimetlhyl-O-(3-methyl-4- 45 nitrophenyl) phosphorothioate along and the component, 0,0-dimethyl--(2,2-dichlorovinyl) phosphate alone.

TABLE II Pesticidal activity against 2d instar larvae of clay backed cutworm (percent) Composition Rate of dilution X1000 X2000 X4000 X8000 Acorn ositionpreparedinExampleL 100 100 80 40 A 50 o emulsifiable concentrate of O ,O-dirnethyl-O- (3 methy1-4-11itr0- phenyl) phosphorothioate 95 80 50 20 O ,O-dimethyl0-(2,2-dichlorovinyl) phosphate 90 60 20 0 What we claim is:

1. A pesticidal composition comprising a carrier, and as the essential active ingredient, an approximately 1:1 mixture by Weight of 0,0'dimet-hyl-O-(3-methyl-4-nitrophony-l) phosp'horothioate and 0,0-dime0hyl-O-(2,2-dichlorovinyl) phosphate.

2. A pesticidal composition comprising as the essential active ingredient, an approximately 1:1 mixture by weight of 0,0-dim-ethyl-O-(3 methy1-4-nitrophenyl) phosphorothioate and 0,0-dimethyl-O-(2,2-dichlorovinyl) phosphate, and about 10 to 100 weight percent, based on the weight of said mixture of at least one member selected from the group consisting of terpene oil and pine oil.

3. A method for combating insects which attack cruci'ferous plants which comprises applying to said plan-ts an insecticial amount of an approximately 1:1 mixture by Weight of O,O-dimethyLO-( 3smethyl-4-nitrophenyl) phosphorothioate and 0,0'dimethyl-O-(2,2-diehlo'rovinyl) phosphate. 7

References Cited by the Examiner UNITED STATES PATENTS 3,091,565 5/1963 Suzuki 167-30 3,116,201 12/ 1963 Whetstone 16722 OTHER REFERENCES Freer: Chemistry of Pesticides, third edition, D. Van Nostrand Company, Inc., New York, 1955, page 418.

JULIAN S. 'LEVITT, Primary Examiner.

JEROME D. GOLDBERG, Assistant Examiner. 

3. A METHOD FOR COMBATING INSECTS WHICH ATTACK CRUCIFEROUS PLANTS WHICH COMPRISES APPLYING TO SAID PLANTS AN INSECTICIAL AMOUNT OF AN APPROXIMATELY 1:1 MIXTURE BY WEIGHT OF O,O-DIMETHYL-O-(3-METHYL-4-NITROPHENYL) PHOSPHOROTHIATE AND O,O-DIMETHYL-O-(2,2-DICHLOROVINYL) PHOSHATE. 